Composite materials incorporating certain particles such as metal oxide particles, for example, can be useful if the particles are compatible with surrounding matrix materials, usually organic polymers. One technique to achieve compatibility is by the chemical modification of the surface of the particle.
Techniques for accomplishing the surface modification of particles are known. For example, hydrolyzed alkoxysilane can be reacted with hydroxyl groups on the surface of metal oxide particles to provide silane functionalized particles. In batch reactor systems operated at or below the boiling point of the solvent solution (e.g., mixture of water and alcohol), these reactions can take anywhere from two hours up to about 24 hours to complete. The lengthy reaction time for this surface modification process has kept manufacturing costs high. Because of the high cost, economic uses for functionalized particles have been limited.